NSData到NString转换问题 [英] NSData to NString conversion problem

问题描述

我得到一个HTML文件作为NSData，需要提取它的一些部分。为此，我需要将其转换为NSString与UTF8编码。事情是这种转换失败，可能是因为NSData包含对UTF8无效的字节。我已经尝试获取数据的字节数组，然后再过来，但是每次遇到非ASCII字符（例如希伯来字母），我都会得到jibrish。

帮助将不胜感激。

更新：

向Gordon生成的NSData：

  NSData * theData = [NSURLConnection sendSynchronousRequest：theRequest returnedResponse：& theResponse错误：& theError]; 
  

当我说转换失败时，我的意思是

  [[NSString alloc] initWithData：temp encoding：NSUTF8StringEncoding] 
  

返回nil

对于Ed - 这是我的代码（我从NSData获得了Byte数组，找到了我需要的，并从中构造了另一个Byte数组 - 将其转换为NSData，然后尝试将其转换为NSString ...听起来很复杂...）

   - （NSString * ）UTF8StringFromData：（NSData *）theData {
 Byte * arr = [theData bytes]; 
 NSUInteger begin1 = [self findIndexOf：@< li> bArr：arr size：[theData length]] + 4; 
 NSUInteger end1 = [self findIndexOf：@< / li>< / ol> bArr：arr size：[theData length]]; 
字节* arr1 =（字节*）malloc（sizeof（Byte）*（（end1-begin1 + 1）））; 
 NSLog（@％d％d，begin1，end1）; 
 int j = 0; （int i = begin1; i< end1; i ++）
 {
 arr1 [j] = arr [i]; 
 j ++; 
} 
 arr1 [j] ='\0'; 
 NSData * temp = [NSData dataWithBytes：arr1 length：j]; 
 
 return [[NSString alloc] initWithData：temp encoding：NSUTF8StringEncoding]; 
  

}

解决方案

我知道这是一个老主题，但是当我在寻找解决方案时，它已经出现了。我现在已经解决了，所以我只是发布给可能遇到这个页面的其他人寻找一个解决方案。

这是我在异步请求中所做的：

我首先在连接中存储文本编码名称：didReceiveResponse使用

然后在我的connectionDidFinishLoading方法后面我使用

  NSStringEncoding encoding = CFStringConvertEncodingToNSStringEncoding（CFStringConvertIANACharSetNameToEncoding（（CFStringRef）encodingName））; 
 NSString * payloadAsString = [[NSString alloc] initWithData：receivedData encoding：encoding]; 
  

I'm getting an HTML file as NSData and need to extract some parts of it. For that I need to convert it to NSString with UTF8 encoding. The thing is that this conversion fails, probably because the NSData contains bytes that are invalid for UTF8. I have tried to get the byte array of the data and go over it, but each time I come across non ASCII character (hebrew letters for example) I get jibrish.

Help will be appreciated.

UPDATE:

To Gordon - the NSData generated like that:

    NSData *theData = [NSURLConnection sendSynchronousRequest:theRequest returningResponse:&theResponse error:&theError];

When I say that the conversion fails I mean that

[[NSString alloc] initWithData:temp encoding:NSUTF8StringEncoding]

returns nil

To Ed - Here is my code (I got the Byte array from NSData, found what I need, and constructed another Byte array from that - turned it to NSData and then attempted to convert it to NSString... sounds kinda complicated...)

-(NSString *)UTF8StringFromData:(NSData *)theData{
Byte *arr = [theData bytes];
NSUInteger begin1 = [self findIndexOf:@"<li>" bArr:arr size:[theData length]]+4;
NSUInteger end1 = [self findIndexOf:@"</li></ol>" bArr:arr size:[theData length]];
Byte *arr1 = (Byte *)malloc(sizeof(Byte)*((end1-begin1+1)));
NSLog(@"%d %d",begin1, end1);
int j = 0;
for (int i = begin1; i < end1; i++){
    arr1[j] = arr[i];
    j++;
}
arr1[j]='\0';
NSData *temp = [NSData dataWithBytes:arr1 length:j];

return [[NSString alloc] initWithData:temp encoding:NSUTF8StringEncoding];

}

解决方案

I know this is an old topic but it came up when I was looking for the solution today. I've solved it now so I'm just posting it for others who might run into this page looking for a solution.

Here's what I do in an asynchronous request:

I first store the text encoding name in connection:didReceiveResponse using

encodingName = [[NSString alloc] initWithString:[response textEncodingName]];

Then later in my connectionDidFinishLoading method I used

NSStringEncoding encoding = CFStringConvertEncodingToNSStringEncoding(CFStringConvertIANACharSetNameToEncoding((CFStringRef) encodingName));
NSString *payloadAsString = [[NSString alloc] initWithData:receivedData encoding:encoding];

这篇关于NSData到NString转换问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！